EP1238455B1 - Procede et appareil permettant de generer un signal radiofrequence - Google Patents

Procede et appareil permettant de generer un signal radiofrequence

Info

Publication number
EP1238455B1
EP1238455B1 EP00980198A EP00980198A EP1238455B1 EP 1238455 B1 EP1238455 B1 EP 1238455B1 EP 00980198 A EP00980198 A EP 00980198A EP 00980198 A EP00980198 A EP 00980198A EP 1238455 B1 EP1238455 B1 EP 1238455B1
Authority
EP
European Patent Office
Prior art keywords
signal
predistortion
analog
amplifier
digital
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP00980198A
Other languages
German (de)
English (en)
Other versions
EP1238455A1 (fr
Inventor
Allan Leyonhjelm Scott
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Priority to EP00980198A priority Critical patent/EP1238455B1/fr
Publication of EP1238455A1 publication Critical patent/EP1238455A1/fr
Application granted granted Critical
Publication of EP1238455B1 publication Critical patent/EP1238455B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/62—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/32—Modifications of amplifiers to reduce non-linear distortion
    • H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits

Definitions

  • the present invention relates to a method and an apparatus for generating a radio frequency (RF) signal, and more particularly to linear amplification of radio frequency signals.
  • RF radio frequency
  • RF power amplifiers are inherently non-linear devices since they generate unwanted intermodulation products, which manifest themselves as spurious signals in the amplified output signal, separate and distinct from the input signal.
  • the distortion introduced by an RF amplifier causes the phase and amplitude of its amplified output signal to depart from the phase and amplitude, respectively, of the input signal.
  • Predistortion is a method that modifies the original input signal to the power amplifier such that it is complementary to the distortion characteristics of the power amplifier.
  • the cascaded response of complementary predistortion and amplifier distortion should therefore result in a linear response.
  • the complementary predistortion function is based on the approximation of the amplifier being modelled by a power or a voltera series (otherwise known as the AM/AM & AM/PM).
  • the complementary predistortion function could also include higher order effects, such as thermal properties of the transistor and/or frequency dependent properties due to the bias and matching circuits.
  • Predistortion can be applied at radioor Intermediate frequencies, known as analog predistortion, or applied at baseband, known as digital predistortion. Additionally, to achieve excellent linearity, adaption of the predistortion means is needed to circumvent changes due temperature, component ageing etc.
  • the predistortion mechanism may be made adaptive by extracting the error distortion signal component at the output of the RF amplifier and adjusting the predistortion means in accordance with the extracted error behaviour of the RF amplifier during real-time operation, so as to effectively continuously minimize distortion at the amplifier's output.
  • a good overview of digital predistortion adaptive means is given in J. K. Cavers, "Amplifier linearisation by adaptive predistortion", US patent 5,049,832.
  • International patent applications WO 99/45638 and WO 99/45640 provide examples of an analog predistortion adaptive method.
  • Analog predistortion typically has a limited dynamic (operation)range and is therefore only able to produce limited performance improvements. Analog predistortion, however, can operate over large bandwidths.
  • adaptive digital predistortion is able to produce, in theory, the excellent matching properties required to achieve significant improvements in linearity.
  • the predistortion occurs at baseband, it needs to be converted to radio frequency before it can be amplified.
  • the frequency conversion takes place in the analog domain, which by its nature destroys the perfect matching capabilities of the digital domain. This results in that also digital predistortion becomes limited in respect of performance and bandwidth compared to analog predistortion.
  • amplitude ripple and phase ripple are the basic mechanisms for destroying the digital domain's matching qualities. Both of these quantities are directly linked to the amount of performance improvement that can be obtained. As the amplitude and phase ripple quantities increase, the obtainable linearity performance improvement becomes reduced, regardless of how well matched the complementary function is in the digital domain.
  • Analog and digital predistortion linearisation are typically implemented as standalone techniques, because of practical implementation problems arising from the fact that the two solutions require different architectures for implementation. This is best illustrated in the following two examples.
  • the Power Amplifier is a module that fits in one part of the rack, sometimes included with the frequency conversion circuits.
  • the digital base band processing circuits physically reside in another part of the rack. These two components are physically separated and the signals are communicated via a coaxial cable.
  • the PA is at the top of the mast and the base band processing part is at the base of the mast.
  • the digital baseband processing parts and the PA module are physically separated, which introduces practical implementation problems.
  • Predistortion is a quasi-closed loop power amplification system, as opposed to a closed loop system.
  • Closed loop systems are based on feedback, i.e. cartesian feedback, envelope feedback, polar feedback.
  • quasi-closed loop systems are that both narrowband and wideband systems of an order of magnitude of 10's of MHz can be used.
  • closed systems are limited to narrow band signals of an order of magnitude of 100's of kHz for practical stability reasons, although they can usually achieve higher levels of linearisation than quasi-closed loop systems.
  • feedforward amplification can be used that can result in both high levels of linearity and transmittance of wideband signals. As compared to predistortion methods this requires a rather complicated gain and phase tracking mechanism to keep the loops in balance and results in low power efficiency.
  • the feedforward architecture is currently the most widely used technique for linearising applications in wideband radio. For wideband radio applications, predistortion, both analog and digital methods, in general is characterized by good power efficiency, as compared to the use of the feedforward methods, although they have lower linearity performance than feedforward.
  • Y the output signal
  • X the input signal
  • the frequency conversion circuitry is designed such that Y is linearly related to X, and this assumption is relevant to narrow band signals.
  • This frequency dependence destroys perfect digital predistortion matching properties, and therefore limits the amount of linearisation.
  • the dependence on frequency can be reduced, but it becomes expensive, if not impractical, to design over a wide bandwidth with very low amplitude and phase ripple. That is, low enough amplitude and phase ripple allowing digital predistortion to achieve the desired level of linearity.
  • a digital frequency equaliser could be used to negate the frequency upconverter's frequency dependence. However, there will always exist some residual frequency dependence that limits the amount of linearisation, and it will also increase the complexity of the solution.
  • the method of the invention for linearisation of a radio frequency (RF) power amplifier by predistortion comprises the steps of receiving a digitized base-band input signal, to be amplified by said RF power amplifier, performing digital predistortion of the signals to compensate for amplifier distortion, converting the signal to an analog signal via two D/A converters, performing analog frequency conversion to achieve a radio frequency (RF) signal, performing analog predistortion of the RF signal, amplifying the analog predistorted signal by said RF power amplifier.
  • RF radio frequency
  • the power amplifier of the invention is characterized by means for performing the above steps of the invention.
  • the digitally predistorted signal could be converted to a low digital intermediate frequency in the method and the power amplifier of the invention, whereafter the signal can be converted to an analog signal by using only one D/A converter.
  • Both of these solutions can also be used in such another architecture of the invention, wherein the received base-band input signal can be split into two signals of 90° phase difference, whereafter the rest of the steps of the method of the invention is performed for each of the signals.
  • the predistortion can be made adaptive to further improve the performance and/or circumvent changes due to temperature, component ageing etc.
  • the invention has several advantages as compared to prior predistortion solutions. By solving the upconversion problems caused by the digital predistortion process by splitting the performance requirements between digital and analog predistortion, improved linearity is achieved compared to digital predistortion alone.
  • the solution of the invention also gives a higher efficiency compared to feedforward linearisation techniques, especially for wide band systems.
  • the invention also has the advantage of reduced requirements on frequency conversion parts since the linearisation performance now partly is handled by the analog predistortion means. This results in a cheaper frequency conversion solution.
  • One of the merits of the invention also lies in the fact that the overall performance improvement can be enhanced by splitting it between digital predistortion and analog predistortion. For example, if the basic amplifier gives a performance of -30dBc and 30dB improvement is required, an overall performance of the linearisation of -60dBc is needed. Then digital predistortion could obtain an improvement of 20 dB and the analog predistortion one of 10dB. This makes a total linearisation solution possible, which is very difficult practically or impossible to achieve with digital or analog predistortion alone. For digital predistortion to achieve this alone would require stringent design requirements on the frequency upconverter resulting in either an impossible design requirement or a very expensive solution. For analog predistortion to achieve this alone would require excellent matching of the complementary predistortion function and amplifier distortion function, and analog parts with excellent matching characteristics are very difficult and expensive to produce.
  • Another merit of the invention is that it combines the natural strengths of analog and digital predistortion. That is analog predistortion has limited correction capabilities over a large frequency range, whilst digital predistortion has excellent correction capabilities over a narrower frequency range. The combination can therefore yield improved correction capabilities over all frequency ranges when compared to either digital or analog predistortion techniques alone.
  • a digitized complex baseband input signal S in is first predistorted, as indicated by block 1, to produce a complex baseband digital predistorted output signal S out . More particularly, this is done in a manner to be complementary with respect to a combination of an analog predistorter and a power amplifier, discussed further below and indicated by blocks 4 and 5, respectively. This combination of an analog predistorter and a power amplifier can be thought of as forming a linear power amplifier.
  • the complex baseband digital predistorted signal S out is then converted to an analog signal by two Digital to Analog Converters (DAC), indicated at 2.
  • DAC Digital to Analog Converters
  • the baseband digital predistorted signal S out can be first digitally frequency converted, before being converted to an analog signal via a single DAC.
  • the output from the DAC is then frequency converted by frequency conversion circuits, indicated by block 3, to a radio frequency signal RF in .
  • the frequency conversion circuits 3 can consist of mixers, filters, amplifiers etc. arranged in a manner obvious to a man skilled in the art.
  • the frequency conversion process introduces frequency dependent amplitude and phase ripple, that partly destroys the linearisation ability that can be achieved with digital predistortion alone.
  • the signal RF in containing the frequency converted digitally predistorted signal is now exposed to analog predistortion as indicated by block 4, in a complementary manner with respect to the power amplifier 5.
  • the RF predistorted signal, RF out is then passed through the power amplifier 5 before being transmitted by an antenna 6.
  • the digital and analog predistorters 1 and 4 can optionally be made adaptive to further improve the linear performance and/or circumvent changes due to temperature & ageing etc.
  • the adaption operation which can be carried out with methods well known in art, is indicated by dotted lines ended by an arrow at each one of the blocks 1 and 4 in Fig. 1.
  • FIG. 2 schematically illustrates a so called Doherty amplifier.
  • the architecture of a Doherty amplifier is e.g. described in "RF Power Amplifiers for Wireless Communications" by Steve C. Cripps (ISBN 0-89006-989-1, Artech House, 685 Canton Street, Norwood MA 02062).
  • the Doherty amplifier constitutes an efficiency enhancement technique as compared to a one amplifier device technique, but does not introduce any linearisation improvements.
  • an incoming base band signal S in is quadrature split, indicated by block 7, into two signals with 90° phase difference.
  • the two signals are amplified by the amplifier devices 5, 5', combined as indicated by block 15, and then transmitted by an antenna 6.
  • the performance of the Doherty amplifier can be improved with respect to linearisation by introducing therein the solution of the present invention, as described with reference to Fig. 1.
  • the incoming base band signal S in is first split, indicated by block 7, into a first signal S in being identical to the input signal, and a second signal S in90° being 90 degrees phase shifted.
  • the 90 degree phase shift can be implemented by the so called Hilbert Transform, or according to other methods obvious to a man skilled in the art.
  • the two signals S in and S in90° are processed in each a path containing the same type of function blocks as in Fig. 1, described earlier, said paths extending in parallel from block 7 to a combiner indicated by block 15.
  • the top path blocks are numbered 1, 2, 3, 4 and 5 as in Fig. 1, whereas the lower path blocks are numbered 1', 2', 3', 4' and 5'.
  • the top path, receiving the original signal includes the main power amplifier 5, whereas the lower path, receiving the 90 degrees phase shifted signal, includes a peak or auxiliary amplifier 5'.
  • the output signals from the amplifiers 5 and 5' are combined in the combiner 15 after the signal of the top path having been shifted by 90 degrees.
  • the combination may be implemented as a quarter wave delay after the main power amplifier 5 output.
  • the combined output signal from the combiner 15 is then transmitted by the antenna 6.
  • FIGS 4 and 5 illustrate some simple examples of digital and analog predistortion methods that can be used in connection with the invention, assuming in these Figures that the amplifier is memoryless. What is referred to is use of AM/AM (amplitude modulation/amplitude modulation), AM/PM (amplitude modulation/phase modulation) model of amplifier.
  • AM/AM amplitude modulation/amplitude modulation
  • AM/PM amplitude modulation/phase modulation
  • Figure 4 illustrates an example of a method for implementing digital predistortion of the kind referred to by block 1 in Fig. 1.
  • the digital predistorter in this case is assumed to compensate for the combination of the analog predistorter and power amplifier with a memoryless non-linearity and is based on cartesian complex gain predistortion.
  • Other memoryless predistorter examples could include polar complex gain or full cartesian mapping, the principles of which are described in US patent 5,049,832.
  • the complex baseband input digital signal S in of Fig. 1 is received by an address generator 8.
  • the address generator 8 generates an address based on a function of the amplitude of the signal, this being consistent with the memory non-linearity assumption of the power amplifier.
  • the address is typically the amplitude or power of S in and is used to select a complementary complex gain, S corr , from correction (predistortion) tables 9 for the digital sample in question.
  • the correction tables 9 contain the total complementary complex gain of the combination of the analog predistorter 4 and power amplifier 5, such that the combination of the complementary gain of the digital predistorter 1, the analog predistorter 4 and the power amplifier 5 results in linear gain and phase for all input signal magnitudes.
  • the complementary complex gain sample, S corr , and the orignal input signal sample, S in are then processed by a complex multiplier 10.
  • the output of the complex multiplier 10, S out is designed to linearise the combination of the analog predistorter and power amplifier.
  • the signals used in Figure 4 are complex, which is indicated by the number 2 at the signal paths.
  • Figure 5 illustrates an example of performing 3 rd order analog RF predistortion of the kind referred to by reference number 4 in Figure 1.
  • the digitally predistorted signal converted to RF forms an input RF in to the analog predistorter 4.
  • the RF in signal is delayed, as indicated by block 11, to ensure that RF signal and correction signals coincide at multipliers 13, 13'.
  • the delayed Rf in signal is then split, indicated by block 12, into two signals with quadrature phase, i.e. there is a 90 degree phase shift between the two signals.
  • Both of the quadrature phase signals are then mixed by the multipliers 13 and 13', respectively, with the correction (predistortion) signals I corr and Q corr , respectively.
  • These signals, I corr and Q corr represent the analog complementary complex gain of the amplifier.
  • the resulting mixed signals are then phase combined in a hybrid combiner 14.
  • the output of the analog predistorter, RF out is designed to linearise the power amplifier.
  • the correction signals, I corr and Q corr are generated by first squaring, as indicated by squaring function block 18, the input signal RF in , then filtering, as indicated by filtering function block 19, away unwanted harmonics generated by the squaring function 18, and finally multiplying, as indicated by two blocks 16, the filtered signal from function 19 with two third order coefficients 17, 17'.
  • the two third order coefficients approximate the complementary complex gain of the amplifier.
  • the adjacent channel performance, or linearity performance, of the amplifier is defined as the ratio of the power of a signal to the power of adjacent signal power, on either the lower or the upper sides.
  • the power is calculated by integrating the energy over a bandwidth of 4.096 MHz. For the signal this is shown as the area between the two vertical solid lines, and for the adjacent signal this is shown as the area between the dotted vertical lines.
  • the adjacent channel performance of the given amplifier alone (shown dotted in Figure 6) is 35.8 dBc and 34.4 dBc for the lower and upper adjacent channels respectively.
  • Applying perfect digital predistortion (the ideal complementary function of the given power amplifier) with 0.6dB peak to peak amplitude ripple in the frequency converter results in an adjacent channel performance that (shown solid in Figure 6) is 59.2 dBc and 58.8 dBc for the lower and upper adjacent channels respectively.
  • the performance of the given power amplifier has been improved by digital predistortion by 23.4 and 24.4 dB, however limited by the amplitude ripple in the frequency converter.
  • the given amplifier is first predistorted by a RF analog predistorter.
  • the adjacent channel performance (shown dotted in Figure 7) is 41.1 dBc and 40.6 dBc for the lower and upper adjacent channels respectively.
  • the analog predistorter has improved the given power amplifier by 5.3 dB and 5.2 dB. Notice that the analog predistorter has also improved the higher order distortions (wider frequency range) of the amplifier in this example.
  • Digital predistortion is now applied to the analog predistorter and the given power amplifier.
  • Perfect digital predistortion (the ideal complementary function of the analog predistorter and given power amplifier) with 0.6dB peak to peak amplitude ripple in the frequency converter results in an adjacent channel performance (shown solid in Figure 7) of 63.1 dBc and 62.8 dBc for the lower and upper adjacent channels respectively.
  • adjacent channel performance shown solid in Figure 7
  • 63.1 dBc and 62.8 dBc for the lower and upper adjacent channels respectively.
  • the performance of the analog predistorter and given power amplifier has been improved by a further 22 and 22.2 dB with the addition of digital predistortion.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Claims (5)

  1. Procédé pour linéariser par prédistorsion un amplificateur de puissance radiofréquence, comprenant les étapes consistant à :
    a) recevoir un signal d'entrée en bande de base numérisé, devant être amplifié par ledit amplificateur,
    b) effectuer une prédistorsion numérique sur le signal reçu pour compenser la distorsion d'amplificateur,
    c) convertir en une fréquence intermédiaire basse le signal prédistordu de façon numérique,
    d) convertir le signal en un signal analogique par l'intermédiaire d'un convertisseur N/A,
    e) effectuer une conversion de fréquence analogique pour produire un signal radiofréquence,
    f) effectuer une prédistorsion analogique sur le signal radiofréquence,
    g) amplifier par ledit amplificateur le signal prédistordu analogique.
  2. Procédé selon la revendication 1, comprenant l'accomplissement de l'étape de prédistorsion analogique d'une manière adaptative, en extrayant une composante de signal d'erreur à partir du signal de sortie de l'amplificateur, en vue de l'utilisation pour régler le signal prédistordu conformément à un comportement d'erreur de l'amplificateur.
  3. Procédé selon la revendication 1 ou 2, comprenant l'accomplissement de l'étape de prédistorsion numérique de manière adaptative, en extrayant une composante de signal d'erreur à partir du signal de sortie de l'amplificateur, et en réglant le signal de prédistorsion conformément au comportement d'erreur de l'amplificateur dans le fonctionnement en temps réel.
  4. Amplificateur de puissance pour l'anplification linéaire de signaux radiofréquence (RF), comprenant
    a) un moyen pour recevoir un signal d'entrée en bande de base,
    b) un moyen pour effectuer une prédistorsion numérique sur le signal d'entrée,
    c) un moyen pour convertir en une fréquence intermédiaire basse le signal prédistordu de façon numérique,
    d) un moyen pour effectuer une conversion N/A du signal obtenu par l'élément c),
    e) un moyen pour effectuer une conversion de fréquence analogique pour obtenir un signal radiofréquence (RF),
    f) un moyen pour effectuer une prédistorsion analogique,
    g) un moyen pour effectuer une amplification sur le signal de l'élément f).
  5. Amplificateur de puissance pour l'amplification linéaire de signaux radiofréquence (RF), comprenant
    a) un moyen pour recevoir un signal d'entrée en bande de base,
    b) un moyen pour diviser le signal d'entrée reçu en deux signaux ayant une différence de phase de 90°,
    c) des première et seconde structures de chemin pour recevoir chacun des deux signaux divisés obtenus dans l'élément b), chacune de ces première et seconde structures de chemin incluant
    c1) un moyen pour effectuer une prédistorsion numérique du signal respectif,
    c2) un moyen pour convertir en une fréquence intermédiaire basse le signal prédistordu de façon numérique,
    c3) un moyen pour effectuer une conversion N/A du signal résultant de l'élément c2),
    c4) un moyen pour effectuer une conversion de fréquence analogique sur le signal résultant de l'élément c3), pour produire un signal radiofréquence,
    c5) un moyen pour effectuer une prédistorsion analogique sur le signal résultant de l'élément c4),
    d) un moyen pour combiner les signaux traités.
EP00980198A 1999-11-24 2000-11-23 Procede et appareil permettant de generer un signal radiofrequence Expired - Lifetime EP1238455B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP00980198A EP1238455B1 (fr) 1999-11-24 2000-11-23 Procede et appareil permettant de generer un signal radiofrequence

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP99850179A EP1104093A1 (fr) 1999-11-24 1999-11-24 Procédé et dispositif de génération d'un signal radiofréquence
EP99850179 1999-11-24
PCT/SE2000/002312 WO2001039367A1 (fr) 1999-11-24 2000-11-23 Procede et appareil permettant de generer un signal radiofrequence
EP00980198A EP1238455B1 (fr) 1999-11-24 2000-11-23 Procede et appareil permettant de generer un signal radiofrequence

Publications (2)

Publication Number Publication Date
EP1238455A1 EP1238455A1 (fr) 2002-09-11
EP1238455B1 true EP1238455B1 (fr) 2006-10-04

Family

ID=8243774

Family Applications (2)

Application Number Title Priority Date Filing Date
EP99850179A Withdrawn EP1104093A1 (fr) 1999-11-24 1999-11-24 Procédé et dispositif de génération d'un signal radiofréquence
EP00980198A Expired - Lifetime EP1238455B1 (fr) 1999-11-24 2000-11-23 Procede et appareil permettant de generer un signal radiofrequence

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP99850179A Withdrawn EP1104093A1 (fr) 1999-11-24 1999-11-24 Procédé et dispositif de génération d'un signal radiofréquence

Country Status (8)

Country Link
US (1) US6947711B1 (fr)
EP (2) EP1104093A1 (fr)
JP (1) JP4679021B2 (fr)
KR (1) KR100806427B1 (fr)
AT (1) ATE341855T1 (fr)
AU (1) AU1749201A (fr)
DE (1) DE60031160D1 (fr)
WO (1) WO2001039367A1 (fr)

Families Citing this family (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE516847C2 (sv) * 2000-07-07 2002-03-12 Ericsson Telefon Ab L M Sammansatt förstärkare samt sändare som innefattar en sådan förstärkare
SE519220C2 (sv) * 2001-06-14 2003-02-04 Ericsson Telefon Ab L M Predistortion med förbikopplingssignal
US7058369B1 (en) 2001-11-21 2006-06-06 Pmc-Sierra Inc. Constant gain digital predistortion controller for linearization of non-linear amplifiers
JP3502087B2 (ja) * 2002-05-14 2004-03-02 松下電器産業株式会社 ハイブリッド歪補償方法およびハイブリッド歪補償装置
JP2004221646A (ja) * 2003-01-09 2004-08-05 Nec Corp ドハ−ティ増幅器
JP2004222151A (ja) 2003-01-17 2004-08-05 Nec Corp ドハーティ増幅器
JP4033794B2 (ja) 2003-03-24 2008-01-16 株式会社エヌ・ティ・ティ・ドコモ 高効率線形電力増幅器
JP2004312344A (ja) * 2003-04-07 2004-11-04 Hitachi Kokusai Electric Inc 歪補償装置
JPWO2005124994A1 (ja) * 2004-06-18 2008-04-17 三菱電機株式会社 高効率増幅器
US7193473B2 (en) * 2005-03-24 2007-03-20 Cree, Inc. High power Doherty amplifier using multi-stage modules
KR100756041B1 (ko) * 2005-06-27 2007-09-07 삼성전자주식회사 믹서를 이용한 도허티 증폭장치 및 송신기
US7831221B2 (en) 2005-12-13 2010-11-09 Andrew Llc Predistortion system and amplifier for addressing group delay modulation
US7856073B2 (en) * 2005-12-14 2010-12-21 Sigma Tel, Inc. Digital gain adjustment in a wireless receiver
JP4704936B2 (ja) * 2006-03-08 2011-06-22 株式会社日立国際電気 プリディストータ
DE102006020831B4 (de) * 2006-05-04 2014-08-28 Siemens Aktiengesellschaft Regler für einen Hochfrequenzverstärker
JP5242024B2 (ja) * 2006-06-08 2013-07-24 株式会社東芝 歪補償装置、増幅装置、送信装置、歪補償方法
US8095088B2 (en) * 2007-05-17 2012-01-10 Harris Stratex Networks Operating Corporation Compact wide dynamic range transmitter for point to point radio
US8275071B2 (en) 2007-05-17 2012-09-25 Harris Stratex Networks Operating Corporation Compact dual receiver architecture for point to point radio
US7782765B2 (en) 2007-01-22 2010-08-24 Harris Stratex Networks Operating Corporation Distributed protection switching architecture for point-to-point microwave radio systems
US8395256B2 (en) * 2007-02-02 2013-03-12 Harris Stratex Networks Operating Corporation Packaging for low-cost, high-performance microwave and millimeter wave modules
US7541868B2 (en) * 2007-05-31 2009-06-02 Andrew, Llc Delay modulator pre-distortion circuit for an amplifier
GB201103642D0 (en) * 2011-03-03 2011-04-13 Univ Bradford Methods and systems for detection of liquid surface fluctuations
US8548404B2 (en) * 2011-09-30 2013-10-01 Scintera Networks, Inc. Linearization of power amplifiers through digital in-band predistortion followed by analog predistortion
US8649745B2 (en) 2011-12-21 2014-02-11 Telefonaktiebolaget L M Ericsson (Publ) Adaptive predistortion for a non-linear subsystem based on a model as a concatenation of a non-linear model followed by a linear model
US9374044B2 (en) * 2011-12-21 2016-06-21 Telefonaktiebolaget L M Ericsson (Publ) Architecture of nonlinear RF filter-based transmitter
US9819318B2 (en) 2011-12-21 2017-11-14 Telefonaktiebolaget L M Ericsson (Publ) Architecture of a low bandwidth predistortion system for non-linear RF components
US8811532B2 (en) 2012-03-16 2014-08-19 Telefonaktiebolaget L M Ericsson (Publ) Architecture and the training method of a PA DPD system with space mapping applied in the predistorter
JP2015099972A (ja) * 2013-11-18 2015-05-28 三菱電機株式会社 送信機モジュール
JP2017046122A (ja) * 2015-08-25 2017-03-02 住友電気工業株式会社 歪補償装置
JPWO2018159021A1 (ja) * 2017-03-02 2019-03-14 住友電気工業株式会社 歪補償装置及び歪補償方法
US10454427B2 (en) * 2017-11-01 2019-10-22 Mitsubishi Electric Research Laboratories, Inc. Power amplifier system and learning-based autotuning method thereof
US10432240B1 (en) 2018-05-22 2019-10-01 Micron Technology, Inc. Wireless devices and systems including examples of compensating power amplifier noise
CN109921750B (zh) * 2019-01-24 2023-05-26 杭州电子科技大学 一种基于有源负载调制的宽带功率放大器及其设计方法
US10763905B1 (en) 2019-06-07 2020-09-01 Micron Technology, Inc. Wireless devices and systems including examples of mismatch correction scheme
US10972139B1 (en) 2020-04-15 2021-04-06 Micron Technology, Inc. Wireless devices and systems including examples of compensating power amplifier noise with neural networks or recurrent neural networks
US11496341B2 (en) 2020-08-13 2022-11-08 Micron Technology, Inc. Wireless devices and systems including examples of compensating I/Q imbalance with neural networks or recurrent neural networks
WO2023141444A1 (fr) * 2022-01-18 2023-07-27 Qorvo Us, Inc. Prédistorsion hybride dans un circuit de transmission sans fil
CN114915266B (zh) * 2022-05-11 2023-08-11 锐石创芯(深圳)科技股份有限公司 射频放大电路和射频前端模组

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4291277A (en) * 1979-05-16 1981-09-22 Harris Corporation Adaptive predistortion technique for linearizing a power amplifier for digital data systems
DE3445551A1 (de) * 1984-12-14 1986-06-19 Robert Bosch Gmbh, 7000 Stuttgart Verfahren zur adaptiven entzerrung von binaer codierten datensignalen
US5049832A (en) 1990-04-20 1991-09-17 Simon Fraser University Amplifier linearization by adaptive predistortion
JPH0746049A (ja) * 1993-07-30 1995-02-14 Toshiba Corp 高周波線形電力増幅器
US5732333A (en) * 1996-02-14 1998-03-24 Glenayre Electronics, Inc. Linear transmitter using predistortion
US5898338A (en) * 1996-09-20 1999-04-27 Spectrian Adaptive digital predistortion linearization and feed-forward correction of RF power amplifier
US5745006A (en) * 1996-11-12 1998-04-28 Motorola, Inc. Method of compensating for distortion in an amplifier
JPH10145161A (ja) * 1996-11-13 1998-05-29 Nec Corp プリディストーション自動調整回路
JPH10322137A (ja) * 1997-05-20 1998-12-04 Matsushita Electric Ind Co Ltd プリディストーション型歪補償回路付送信装置
GB9804835D0 (en) 1998-03-06 1998-04-29 Wireless Systems Int Ltd Predistorter
GB9804745D0 (en) 1998-03-06 1998-04-29 Wireless Systems Int Ltd Predistorter

Also Published As

Publication number Publication date
EP1238455A1 (fr) 2002-09-11
KR20020053090A (ko) 2002-07-04
EP1104093A1 (fr) 2001-05-30
ATE341855T1 (de) 2006-10-15
KR100806427B1 (ko) 2008-02-21
AU1749201A (en) 2001-06-04
DE60031160D1 (de) 2006-11-16
US6947711B1 (en) 2005-09-20
WO2001039367A1 (fr) 2001-05-31
JP2003516013A (ja) 2003-05-07
JP4679021B2 (ja) 2011-04-27

Similar Documents

Publication Publication Date Title
EP1238455B1 (fr) Procede et appareil permettant de generer un signal radiofrequence
US10728066B2 (en) Modulation agnostic digital hybrid mode power amplifier system and method
Katz et al. The evolution of PA linearization: From classic feedforward and feedback through analog and digital predistortion
Hoversten et al. Codesign of PA, supply, and signal processing for linear supply-modulated RF transmitters
Woo et al. A hybrid digital/RF envelope predistortion linearization system for power amplifiers
US6963242B2 (en) Predistorter for phase modulated signals with low peak to average ratios
EP2143209B1 (fr) Système d'amplification de puissance en mode hybride numérique
US7348843B1 (en) Predistortion linearizer using cascaded lower-order linearizers
Boumaiza et al. Adaptive digital/RF predistortion using a nonuniform LUT indexing function with built-in dependence on the amplifier nonlinearity
US8649744B2 (en) Radio-frequency transmitter, such as for broadcasting and cellular base stations
US7095277B2 (en) Method and arrangement for a power amplifier
CN112042118A (zh) 用于g类射频功率放大器的基带线性化的***和方法
US8023908B2 (en) Intermodulation signal generator of power amplifier and pre-distortion linearizer having the same
Helaoui et al. On the RF/DSP design for efficiency of OFDM transmitters
Katz et al. Truly wideband linearization
Jung et al. A new envelope predistorter with envelope delay taps for memory effect compensation
JP3412594B2 (ja) 歪補償回路
Katz et al. The evolution of linearizers for high power amplifiers
EP1394954B1 (fr) Emetteur
Woo et al. Wideband predistortion linearization system for RF power amplifiers using an envelope modulation technique
JP3467670B2 (ja) 歪補償回路
Katz et al. Ka/q dual band linearizer
Patel Adaptive digital predistortion linearizer for power amplifiers in military UHF satellite
White et al. Linearization of RF Frontends White Paper
Qiu et al. TWT performance enhancement using higher-order predistortion linearization techniques

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20020518

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RBV Designated contracting states (corrected)

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20061004

Ref country code: CH

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

Ref country code: LI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 60031160

Country of ref document: DE

Date of ref document: 20061116

Kind code of ref document: P

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20061123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20061130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20070104

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20070104

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20070105

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20070115

ET Fr: translation filed
NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20070705

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20070105

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20061123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20061004

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20141127

Year of fee payment: 15

Ref country code: FR

Payment date: 20141118

Year of fee payment: 15

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20151123

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20160729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20151130